As the founder and general secretary of the AJ4PM campaign, I found This Boy, AJ’s memoir of his childhood, beautifully written, affecting, and sad.

The same applies to the next volume of his life, taking him from marriage at the age of 17 to election as a national officer of the Union of Communication Workers at the age of 37, although the emotional power of the story is more restrained.

Partly, this is because the story moves from the unfamiliar — a London childhood of exceptional poverty, exceptional in the 1950s, I mean, let alone now — to a life that is more familiar to me. AJ came to politics late, so the failure of the union movement and the Labour government in the 1970s formed him, just as they influenced me, eight years younger.

Yet his book is a wonderful elegy for a life that has only just passed into history. A time when nobody drank at home, when Post Office vans required double de-clutching and when the “fax machine – believe it or not – was seen as a serious threat to our future”.

Most of the story is of the normal life of a self-taught postman in Slough who becomes increasingly involved in the union. As before, misery and pain are always near: his brother-in-law, the looked-up-to husband of the sister who cared for him as an orphan, was a secret alcoholic who committed suicide.

And, as before, the writing is understated, which makes the deft touches of poetry and erudition all the more effective. After he, his wife and her young daughter were rehoused to Slough (the council house in west London they shared with his mother-in-law was demolished) he read John Betjeman’s poem and knew the intention was to “lament industrialisation and the blighting of England’s landscape in general”, but he disagreed with it. “Having been born into a street that literally wasn’t ‘fit for humans’, I knew the difference between a place that was and one that wasn’t.”

His political opinions, forged in practical experience as a union rep, were equally intolerant of sentiment. Of Arthur Scargill’s insistence that he’d been right about the Coal Board’s plan to close pits, he says: “The job of a trade-union leader isn’t to predict rain, it’s to build a bloody ark.” He says strike-happy officials in his own union were “like pilots who knew how to take off but who’d never been taught to land”.

Yet his own advancement was delayed for the same reason he never made the last step up to be Prime Minister: “My personality was steeped in the self-effacement that held back so many working-class people.” Still, he ended up Education Secretary, Health Secretary, and Home Secretary. He didn’t do so badly.